One session lasts three to four months. While the drug is active the gland is stimulated less and shrinks, and when it wears off the reduced size does not come straight back. With repeat sessions the smaller state holds longer, so the interval is often widened.

Your mouth may feel dry for a while. The signal that triggers saliva is reduced, and most people adjust within a few days and the discomfort passes; drinking water often helps. If chewing continues to feel odd, though, the drug may have spread toward the chewing muscle, so it is worth seeing the doctor.

The fullness under the jaw reduces over two to four weeks, because the gland needs time to actually shrink. The change is only clear when the gland, rather than fat, is the cause, so the consultation includes feeling the area by hand first to work out which it is.